Interesting ImagesExtrarenal Retroperitoneal Angiomyolipoma Mimicking Metastatic Melanoma CT and FDG PET CorrelationWelling, Rodney D. MD; Lungren, Matthew P. MD; Coleman, R. Edward MDAuthor Information From the Department of Radiology, Duke University Medical Center, Durham, NC. Received for publication July 15, 2011; revision accepted October 18, 2011. Conflicts of interest and sources of funding: none declared. Reprints: Rodney D. Welling, MD, Department of Radiology, Duke University Medical Center, Box 3808, Durham, NC 27710. E-mail: [email protected]. Clinical Nuclear Medicine: July 2012 - Volume 37 - Issue 7 - p 705-706 doi: 10.1097/RLU.0b013e3182443c7d Buy Metrics Abstract A 38-year-old man with melanoma of the right flank underwent a staging 18F-fluoro-2-deoxyglucose (FDG) PET/CT scan, which demonstrated a hypermetabolic extrarenal mass in the left retroperitoneal space, concerning for metastatic melanoma. However, surgical pathology demonstrated an angiomyolipoma (AML). Although AMLs can rarely occur in an extrarenal location, extrarenal retroperitoneal AMLs are exceptional. AMLs have variable imaging appearances on multiple imaging modalities, including FDG PET, and can confound accurate diagnosis when in an extrarenal location. This case demonstrates the only known FDG PET description of an extrarenal retroperitoneal AML and highlights the challenge in accurate diagnosis based on FDG PET findings. Copyright © 2012 Wolters Kluwer Health, Inc. All rights reserved.